Brake Fluid Flush

[jhm]

Anyone flushed out thier brake fluid? I got 35K on the clock and am thinking to do this preventive maintenance. The garage owner here in town, who I trust says people don't realize how much moisture builds up. He wasn't pushing the service, just talking in general. I was at the dealership a while back on a warranty issue and they had some article about how the boiling point drops considerably after a few years and the water can start rusting parts out. This would seem easy to do, just like bleeding the brakes. Sounds like cheap insurance to me.

[Ben]

I flush all my vehicle brakes, power steering fluid, tranny fluid, diff fluid min every other year.

 

Brake fluid that starts to discolor, turn dark, has started absorbing moisture and is less effective (lower boiling point).

 

Another thing is to no fill up the MC reservoir on disc brakes. Disc brakes consumes fluid and the MC reservoir is indicator of how much frction material is left. Not absolutely accurate, but good enough to not have to take a wheel off each time, just when rotating check'm

 

Your mechanic gave you excellant advice.

[RyanbabZ71]

it was suggested to me to use a turkey baster to suck out the old fluid.

[JayMan]

I picked up my special order in August of 2000. In October of 2000, changed everything as I had on about 600 miles. I use one of those cheap parts store siphon things to suck out the old fluid from the Master Cylinder.

 

Even from new, you should see the garbage you get out when you crack the bleeder and have somebody tromp the pedal. 600 miles and the brake fluid was almost BLACK.

 

Not only will DOT 3 absorb moisture, it will also age from exposure to heat. I guess you know disk brakes make lots of heat?

 

I also have a "vintage" 1984 Ford F-150 that I also flush out once a year. DOT 3 seems to have a shelf-life once opened, and I figure the shelf life at about a year. So every year I flush out the ancient Ford and the new GMC.

 

Gallon of DOT 3 is about $8 at NAPA, takes 1.5 hours to do both trucks. Very cheap insurance and the brakes work much better afterwards. You wouldn't think they would, but they DO.

 

On the subject, ask me how often I change my power steering fluid! Hint: look above on my brake servicing to get a rough idea.

[marman]

JayMan,

 

How do you flush the power steering fluid? And, how much power steering fluid do you need to flush? Thanks.

[ness5575]

what is the correct way to flush the brake fluid?

use the turkey baster to get the fluid out of the master cylinder, replace with new fluid, and then bleed out of both back brakes till clean fluid comes out???

[JayMan]

JayMan,

 

How do you flush the power steering fluid? And, how much power steering fluid do you need to flush? Thanks.

The Helm shop manual has a very complicated flush procedure for the power steering. I just siphon out as much as I can, take off the return hose and stick it in a bucket, and stick another hose from a full container "donor bottle" of PS fluid into the return port. The donor bottle has to be at a level as high as or higher than the pump.

 

I then jack up the front end so the wheels are off the ground, start the truck, and have somebody slowly turn the steering wheel lock-to-lock while I keep an eye on the level in the donor bottle

 

I have a clear hose hooked up to the return hose so when the fluid runs clear, I stop the procedure and hook the return hose back to the PS pump. Check the level, cap the PS pump, start the motor and do lock-to-lock, shut off, and check the level again.

 

Doing this the first time was nasty as it took forever to get the fluid clean. I recall about 6 quarts of GM Power Steering Fluid. Last fall I switched to the special partial synthetic Low Temp Power Steering Fluid and it took 2 quarts. The first flush will take the most, so you don't want to use that expensive Low Temp PS fluid then!

[JayMan]

what is the correct way to flush the brake fluid?

use the turkey baster to get the fluid out of the master cylinder, replace with new fluid, and then bleed out of both back brakes till clean fluid comes out???

That sounds about right. Don't forget to bleed out the front brakes too, not just the back ones. Your ABS will thank you.

 

With somebody helping you by tromping on the brake pedal while you open the bleed screw, you'll see immediately when the new fluid comes out. It will be clear inside the tube from the brake bleeder.

 

Instead of a Turkey Baster, I use one of those cheap Parts Store siphon things. Not as messy.

[marman]

JayMan,

 

Thanks much for the power steering flush procedure. Sounds like it could be messy, but sure worth doing.

[ness5575]

thanks jayman.

i will give it a shot when it warms up a little (who am i kidding - when it warms up a lot!)